Californians will have more than a month to use the push-button registration system before the Oct. 22 deadline to qualify for casting ballots this year.

More than 6 million people have the right to register to vote, but have not yet done so, according to state records.

California's voter rolls totaled 17.1 million people -- 72 percent of those eligible -- shortly before the June primary election.

Until now, potential voters could fill out a registration form on the secretary of state's website, but they would have to print out and sign a paper copy for signature verification by county elections officials.

The new system will allow the entire registration process to occur electronically, with no paper copy. Applicants will fill out a state form, then submit an electronic signature to be checked against Department of Motor Vehicle records.

Because of the need to coordinate with DMV, the new system can serve only Californians who possess a driver's license or identification card.

Senate Bill 397, which took effect Jan. 1, authorized creation of online registration before California has upgraded its electronic database of state voters as required by federal law.

State Sen. Leland Yee, a San Francisco Democrat who proposed SB 397, said the new system will enable voters to register from the comfort of their home, perhaps in anger or passion after watching a campaign advertisement or speech on TV.

"It's tremendous, it's a game-changer," Yee said, predicting that online registration will become as popular with Californians as vote-by-mail ballots have been in recent elections.

Yee said that some counties also plan to make online registration forms available on their websites, giving potential voters another option.

Many Republicans opposed SB 397, and Yee said that some political observers have speculated that online voter registration would benefit Democrats because so many young people are familiar with computers.

"I just don't believe that; there's no data to support that," Yee said. "When you look at some of the older voters, they're just as sophisticated at using e-mail and doing other things online. I think it's going to be a wash."

Kim Alexander, president of the California Voter Foundation, said the new system will "create an enormously convenient opportunity for thousands and thousands of Californians."

"I think it's going to help everybody," she said when asked which party it benefits most.

Online registration is not without risks. Handling transactions electronically raises the possibility, however remote, of someone hacking into the system, Alexander said.

"You have to take extra measures to protect those systems, but I'm confident the secretary of state has given that a lot of thought," Alexander said.

Other states with online registration include Arizona, Oregon, Washington, Nevada, Utah, New York, Colorado, Indiana, Kansas and Louisiana, Alexander said.

"This new system will not only save the state and counties millions of dollars, but voter information will be secure, data will be accurate, and voters will have ease of access to register to vote," he said.

Paper applications will still be available at county elections offices, DMV offices, and many post offices, libraries and government offices.